has anyone had GD first pregnancy and not the second?

Nicole • Was pregnant last year, missed it so much got prego again!!! . Social worker for the homeless. I have a infant and 4 dogs 🐶🐶🐶🐶 Second pregnancy a year later 😯
I am 15 weeks and I came back negative for GD. Doc said whatever I'm doing keep it up. Is it commen to be negative for for GD for the first test? I take my 3 hour test around 29 weeks... I r ally do not want to be insulin dependent again. Anyone else have experience with this ????